The Cell Library has very little 'file management' functionality. New + delete only.
It would be very helpful to at least provide a Duplicate option to the Right-click menu. A lot of Cells will be quicker to create from an existing Cell. Especially with the increased amount of non-graphic info that needs to be applied (Item Types, Element Templates etc).
It would also support better, more fluid use of components. See this example where room layouts are being saved as reusable components... which also demonstrates the benefits of quick duplication to enable variation.
aka 'Make Unique' in some MCAD apps. This is often used as the first step to creating a new Cell or component. Faster than having to back out and open a separate file to create the new Cell.. out of context.